The element phosphorus was given that name because its white form glows in the dark. Both phospho- and phosphoro- derive from phosphorus, the latter being the older and now less common form.

Examples of words containing phospho- include phosphate, a salt or ester of phosphoric acid; phosphine, a colourless foul-smelling gaseous compound of phosphorus and hydrogen, analogous to ammonia; phospholipid, a lipid containing a phosphate group in its molecule; phosphocreatine, a phosphate ester of creatine found in vertebrate muscle.

Phosphoro- appears in a few terms: phosphorylase, an enzyme which introduces a phosphate group into an organic molecule, notably glucose; phosphorolysis (Greek lusis, loosening), a form of hydrolysis in which a bond in an organic molecule is broken and an inorganic phosphate group becomes attached to one of the atoms previously linked; the adjective phosphorous refers to phosphorus or something containing it; this has a stricter sense in chemistry, referring to phosphorus in its lower, trivalent state, as in phosphorousacid, H3PO3.

Some terms relating to the production of light also derive from phosphorus, such as phosphorescence, light emitted by a substance without combustion or perceptible heat, and phosphor, a synthetic fluorescent or phosphorescent substance.